One embodiment of the present invention provides a method performed by a base station of a macro cell for supporting a carrier aggregation (CA) between the macro cell and at least one small cell in the macro cell, the method comprising: transmitting, to a terminal, user data based on a user plane of the macro cell and control data based on a control plane of the macro cell; transmitting, to the terminal, a configuration message for configuring a small cell of the at least one small cell, in case that the terminal within a coverage of the small cell is identified; generating first control information indicating that the user data is transmitted based on a user plane of the small cell; and transmitting, to the terminal, the generated first control information